Fish counts and reports (fish data) (2024)

Day, night, and winter fish counts from 15 Corps fishladders are reported on these pages.

Day fish counts (4 a.m. - 8 p.m. PST each day from April 1 through Oct. 31 each year) are taken by fish counters looking directly into the fishladders.They count the fish passing by 50 minutes each hour.

To account for the fish that pass by during the breaks they take (160 minutes of break), we add the counts made during the day's counting periods (800 minutes of counting), multiply the total by 1.2, round to the nearest whole fish, and present that number as our estimate of the day count in each ladder.

The fish counters are currently taking separate counts of adult chinook, jack chinook, clipped steelhead, unclipped steelhead, adult coho, jack coho, sockeye, chum, pink, shad, and lamprey.We add the adult chinook and jack chinook day estimates together to get All chinook, clipped steelhead and unclipped steelhead day estimates together to get All steelhead, and adult coho and jack coho day estimates together to get "All" coho.When night (8 p.m. - 4 a.m. PST each day) or winter (Nov. 1 through March 31) fish counts are taken, the fish counters use video, recording and reading the entire 60 minutes of each hour, so no estimation is necessary.

The counting schedules we maintain, which fish species are counted, how the counts are reported, and the methods for expansion or estimations we use aredeterminedby the Fish Passage and Operations Management committee, who are NOAA, CRITFC, ODFW, WDFW, IDFW, BPA, and COE biologists.

Fish counting at the dams was started as each dam was put into service:

• at Bonneville in 1938,
• at McNary in 1954,
• at The Dalles in 1957,
• at Ice Harbor 1962,
• at John Day in 1968,
• at Lower Monumental in 1969,
• at Little Goose in 1970,
• and at Lower Granite in 1975.

Portland District publishes the fish counts taken at the dams in annual fish passage reports, as daily, monthly, and yearly count totals of fish migrating upstream through the fishladders at each dam.

The fishladders assist native populations of returning anadromous chinook, steelhead, sockeye, and coho salmon and lamprey. Chinook (Oncorhynchus tshawytscha), coho (O. kisutch), sockeye (O. nerka), and steelhead (O. mykiss) have been counted steadily.

Pink (O. gorbuscha) and chum (O. keta) are rarely seen above Bonneville. Few are seen at Bonneville each year. No persistent populations of pink are known to exist in the Columbia Basin. A persistent population of chum is known to exist in the Columbia Basin at the Grays River, Hardy Creek, and Hamilton Springs. The Grays River is well below Bonneville Dam. Hardy Creek and Hamilton Springs are only a few kilometers below Bonneville Dam.

The counters have fairly steadily counted two other returning anadromous fish; American shad (Alosa sapidissima) and Pacific lamprey (Lampetra tridentata).

Cutthroat trout (especially anadromous cutthroat trout), which often need to be handled to be identified correctly, are rarely seen by the fish counters.

Bull trout (Salvelinus confluentus) and white sturgeon (Acipenser transmontanus, a diadromous fish) are also counted in the notes the fish counters take. River-resident species of fish, were counted from 1939 through 1969, butare no longer counted.

Since1980:
Jack size chinook (12 inches to under 22 inches) and jack size coho (12 inches to under 18 inches) are counted separately from adult size chinook (22 inches and up) and adult size coho (18 inches and up).

Since1981:
Fish counts from each fishladder (first 2 queries below) go back to 1981. In Portland District annual fish passage reports fishladder counts are combined to get the counts for each dam (Bonneville, The Dalles, John Day, McNary, Ice Harbor, and Lower Monumental each have 2 fishladders). These dam by dam counts (3rd, 4th, and 5th queries below) go back to 1938. Individual fishladder records from before 1981 are either archived (the counts from the fishladders at Bonneville, The Dalles, and John Day are archived) or may be in storage at the other dams, unavailable, or lost.

Since1981, at Bonneville:
The upper section of the Cascades Island fishladder (before 1981 this fishladder was the Washington shore fishladder at Bonneville) is closed to fish passage and upstream migrating fish are rerouted to the Washington shore fishladder. It is occasionally reopened when the Washington shore fishladder is out of service or the channel to the Washington shore fishladder is blocked.

Since1994:
Clipped and unclipped steelhead are counted separately.

SinceJune 1, 2010 at Bonneville:
Lamprey passage systems are in use seasonally.These provide lamprey with alternate routes to take around sections of the Bradford Island and Washington shore fishladders. In the Cascades Island fishladder entrance area, a third LPS leads to a trap. Biologists take the trapped lamprey to sites upriver of Bonneville.